Verrucous Granular Parakeratosis on the Groin: A Case Report.

Granular parakeratosis is a rare dermatosis characterized by erythematous scaly patches or papules, and plaques, often involving intertriginous areas. In this work, a 73-year-old Chinese male patient presented with a 6-month history of pruritic verrucous papules on the bilateral groin. A skin biopsy was performed and revealed the following: the horny layer showed highly compact hyperkeratosis and parakeratosis with basophilic granules; the epidermis showed obvious acanthosis with psoriasiform hyperplasia. The final diagnosis was verrucous granular parakeratosis. We also reviewed the progress in nomenclature, etiology, clinical manifestations, differential diagnosis and treatment. Different clinical manifestations may represent different clinical entities. Dermatologists should differentiate it from other diseases to make a correct diagnosis. Treatment options should be based on the variable etiologies and clinical manifestations.